I have the exact same issue. Funny enough the exact same way. I submitted 2 tickets since release day and have still heard nothing unfortunately.
Mine is locked on my Mesmer in a similar position. I was going to meet with Marjory and Kasmeer, but a guild member was starting the next part and I got a notification to join them and I accidentally hit yes, after completing it with them, I went back to finish mine, to not be able access the instance any longer.
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